NRI and GTS first map the pairwise scores into range \([0,1]\)  (e.g., via softmax or sigmoid). The models use the Gumbel softmax trick [1]}, [2]} to sample a discrete adjacency matrix from the edge probabilities in a differentiable way (though gradients are biased); a downside is that we have to take extra steps to obtain a sparse graph, e.g., by regularization.
